Electric signal system for railways.



No. 712,457. Patented Oct. 28, I902. E. P. JESSOP.

ELECTRIC SIGNAL SYSTEM FOR BAILWAYS.-

(Application filed Apr. 5, 1902.)

(N0.Model.)

32 as 40 44 :2 & /l7 J23 WITNESSES //V VE N TOR Earl Jessqp.

ATTOFNEY m: noflms PETERS 00 PHOYQLITNO. WASHINGTON. a c4 1. danger and will automatically ignite a sig- UNITED STATES PATENT OFFICE.

EARL P. JESSOP, OF THE UNITED STATES NAVY, ASSIGNOR OF ONE-THIRD TO. DUDLEY W. KNOX, OF THE UNITED STATES NAVY.

ELECTRIC SIGNAL SYSTEM FOR RAILWAYS.

SPECIFICATION forming part of Letters Patent No. 712,457, dated October 28, 1902.

Application filed April 5, 1902. Serial No. 101,476. (No model.)

To all whom it may concern.-

Be it known that I, EARL P. JESSOP, of the United States Navy, a citizen of the United States, have invented certain new and useful Improvements in Electric Signal Systems for Railways; and I do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled use the same.

This invention relates to improvements in electric signal systems for railways and is intended to be used as an addition to signals now in use for the purpose of providing greater security and less chance ofaccident.

This invention is designed to act as a signal to the engineer to indicate that a semaphore or other track-signal is's'et to indicate nal-lamp in the cab and apply the brakes to the train in time to preventaccident.

The invention embraces a pair of insulated plates or railslocated adjacent to a semaphore or other signal and includes an electric circuit embracing two fixed contacts and a contact-arm on the moving portion of the semaphore and a battery and signal-actuatin g mechanism on the locomotive. In lieu of a pair of contacts but one may be used, the re turn of the circuit being through the rails. A signal-lamp is ignited and a train -'pipe-- release valve is actuated by means of a magnet embraced in the circuit. The releasevalve is of that type described and illustrated in my application, Serial No. 98,331, filed March 15, 1902.

In order to better understand the nature of my said invention, attention is called to the accompanying drawings, forming a part of this specification, and in which Figure 1 represents a diagrammatic view of the device, partly in perspective. Fig. 2 is a detailed view of the switch, and Fig. 3 a modified form of the device.

In all the several views identical parts are designated by the same numerals of reference. I

But a portion of one rail is shown at 1. Upon this is-conventionally indicated a portion of the running-gear 2 of a car or locomotive, from which depends the pair of contactbrushes 3 and 4. These latter engage, respectively, with contact-platese and 6, which are of comparatively short length and are supported upon insulated blocks 7 7 between the rails. In lieu of the brushes 3 andei trolley-arms canbe substituted, or a double trolley, such as is illustrated and described in my said application, Serial No. 98,331, may be used. The contact-plates may be placed outside of the rails either or both on .the same side, or in lieu of the plates overhead wires mounted upon suitable insulated supports may be employed. The contacts 5 and 6 are connected to plates 8 and 9 by means of the wires 10 and 11. The plates 8 and 9 are adapted to be bridged by a contactarm 12, secured to a standard 13 of a semaphore 14 or other signal. It is to be understood that the particular form of. semaphore shown is merely for the purposes of illustration, as it is the purpose of this invention to embrace any form of signal in which there is a mechanical portion capable of movement, by means of which a circuit may be closed. As shown in Fig. 1, the circuit between the plates 8 and 9 is broken; but it is obvious .that upon a quarter-turn being given to the standard 13 the contact-arm will engage with and bridge over the space between the plates A magnet 15 is located at a convenient point upon the locomotive,'but preferably within the cab thereof, and attracts when excited an armature 16, carried upon an arm 17. The free end of the latter actuates by intermediate mechanism, about to be described, a release-valve 18 and a switch 19. A suitable source of electrical energy-as, for instance,

a battery 20-is provided, and Wires forming c the circuits 21 and 22 from the contacts 5 and 6, respectively, include the magnet 15. Ifthe circuit be completedbetween the plates 8 and 9 by means of the arm 12, the magnet will be excited, the circuit embracing the arms 3 and 4, contact-plates 5 and 6, plates 8 and 9, wires 10 and 11, contact-arm 12, and wires 21 and 22. Upon the magnet becoming excited and the armature 16'depressed the switch 19 will be closed in the manner about-to be described, 103 which action will complete the cab-circuit 23 and 24 and ignite the signal-lamp 25. The

same action will also open the release-valve 18 and apply the brakes to the entire train. The switch above referred to consists of the contacts 27 27, connected to the circuit-Wires 23 24 and adapted to be engaged by the moving contacts 28 28, carried upon the verticallymovable stem 26, the lower end of which is engaged by the free extremity of the lever 17.

The release-valve 18 is substantially as described in my application Serial No. 98,331, above referred to, and consists, essentially, of a main valve and a pilot-valve, the latter actuated by the lever 17. The valve in the present application differs somewhat in detail from that referred to, and a complete description will therefore follow. The main valve consists of a piston-valve 29, which is adapted when in the position shown to close the train-pipe 30 and prevent communication with theexhaust-port 31. The piston-valve 29 is adapted to be lifted by means of a piston 32, connected thereto by a piston-rod 33, the parts being adapted to be operated by train-air admitted below the piston 32 and closed by train-air from above the pistonvalve 29. The pilot-valve 36 consists of a stem or piston-rod, which may be a continuation of the stem 26, if desired, carrying the upper valve and lower valve 34, between which is the inlet-port 38 for the train-air, the latter being supplied by a suitable pipe, as illustrated. The train-air is admitted above the piston-valve 29 by the port 39 and is admitted below the piston 32 by the port 40, the latter being shown closed by the valve 35. The operation of the valve is as follows: The valve being in the position shown train-air from the port 38 will pass through the open passage 39 to the top of the piston-valve 29 and will hold the latter against its seat. The stem 26 being elevated by the action of the arm 17 will by the action of the valve 34 open communication with the exhaust-port 42 and at the same time will open the passage 40 by the movement of the valve 35, thus admitting train-air below the piston 32. This action will lift the piston 32, together with the piston-valve 29, and open communication between the train-pipe 30 and exhaust 31. The

displaced air from abOX G the piston will be exhausted through the port 42. A second port 41 is provided to permit the air from below the piston 32 to exhaust into the atmos phere on a reverse movement of the parts when the main valve is closed. After the piston-valve is opened it may be retained in such open position by means of a hook or latch 43, carried by a spring 44 and having a finger-piece 45 to permit of its disengagement. The stem 26 maybe provided with an enlarged head 46, with which the hook 43 engages. A spring 47 for lowering the free end of the arm 17 and a standard or stop 48 for limiting its movement are provided.

In the operation of the entire device if the semaphore 14'be set to safety the bridgingcontact 12. will break the track-circuit, which includes the contacts 8 and 9. The car carrying the contact-brushes 3 and 4 will cause them to engage with the contact-plates 5 and 6; but the circuit being incomplete between the contacts 8 and 9 the magnet 15 will not be affected and the signal will be inoperative. If the semaphore 14 be set to danger, the bridging-contact 12 will complete the trackcircuit, and upon the contact-brushes 3 and 4 on the car becoming engaged with the contacts 5 and 6 the magnet 15 will be energized, the lamp ignited, and the brakes applied, thus serving as a means for greater safety should the engineer fail to see the danger position of the semaphore. Should the brakes for any reason fail to act, the presence of the ignited signal-lamp on the cab will serve as a warning to the engineer.

The modification illustrated in Fig. 3 cmbraces a lamp arranged in a circuit which is normally closed by means of a switch 51 52, carried upon some moving portion of the deviceas, for instance, the rod 26. This lamp 49, which is preferably arranged to make a white light, is connected in the circuit 50. The danger-signal lamp (designated by the reference 25') is preferably colored. In operation the circuit will be closed so long as the semaphores are set to safety. If one be moved to bridge the contacts 8 and 9 by the arm 12, a circuit will be completed through the two brushes 3 and 4 and the magnet 15 will be energized. It is of course essential that the resistance in the circuit 50 be greater than that in the magnet 15. The latter being energized, will attract its armature and by means of the movement of the arm 17 will break the circuit 50 and then complete the circuit 23 24, which will extinguish the lamp 49 and ignite the signal-lamp 25. The release-valve will at the same time be opened.

Before claiming my invention I wish it understood that I do not wish to be limited to the exact construction shown or described, as the device may be modified in many ways without departing from the spirit of the invention.

Having now particularly described and ascertained the nature of my said invention, what I claim, and desire to secure by Letters Patent, is-

1. The combination, in an electric signal system, with a track-circuit, adapted to be completed by the movement of a track-signal, of a car-circuit embracing a magnet, a releasevalve operated thereby, and a hook for retaining said valve in operative position, substantially as set forth.

2. The combination, in an electric signal system, with a track-circuit, adapted to be completed by the movement of a track-signal, of a car-circuit embracing a magnet, adapted when energized to move an armature, avalve operated by said armature for actuating an air-brake, and a hook for retaining said valve in operative position, substantially as set forth.

3. The combination, in an electric signal system,'with a track-circuit, adapted to be completed by the movement of a track-signal,-

of a car-circuit embracing a magnet, adapted when energized to move an armature, of a pilot-valve operated by said armature for actuating an air-brake, a hook for retaining said valve in operative position, a switch carried by said valve, a circuit adapted to be closed by said switch, anda signal Within said circnit,adapted to be actuated by the closing of said valve, substantially as set forth.

This specification signed and witnessed this 25 2d day of April, 1902.

E. P. JESSOP. \Vitnesses:

W. H. 'WALooTT, BENJAMIN T. BRIGGS. 

